Drawing on the pioneering work of Anthony Downs, political scientists have tended to characterize American politics as a game among undifferentiated competitors, played out largely through elections, with outcomes reflecting how formal rules translate election results into legislative votes. In this perspective, voters, campaigns, elections, and the ideological distribution of legislators merit extensive scrutiny. Other features of the political environment—most notably, the policies these legislators help create and the interest groups that struggle over these policies—are deemed largely peripheral. However, contemporary politics often looks very different than the world described by Downs. Instead, it more closely resembles the world depicted by E. E. Schattschneider—a world in which policy and groups loom large, the influence of voters is highly conditional, and the key struggle is not over gaining office but over reshaping governance. Over the last twenty years, a growing body of scholarship has emerged that advances this corrective vision—an approach we call Jacob S. Hacker and Paul Pierson (2014). After the “Master Theory”: Downs, Schattschneider, and the Rebirth of Policy-Focused Analysis. Perspectives on Politics, 12, pp 643-662. doi:10.1017/S1537592714001637. In this framework, politics is centrally about the exercise of government authority for particular substantive purposes. Such exercises of authority create the “terrain” for political struggle, profoundly shaping both individual and group political behavior. More important, because policies can be so consequential, they also serve as the “prize” for many of the most enduring political players, especially organized interest groups. The payoffs of a policy-focused perspective include a more accurate portrayal of the institutional environment of modern politics, an appreciation for the fundamental importance of organized groups, a better understanding of the dynamics of policy change, and a more accurate mapping of interests, strategies, and influence. These benefits are illustrated through brief examinations of two of the biggest changes in American politics over the last generation: asymmetric partisan polarization and the growing concentration of income at the top.